P450s, and one of its jobs is to convert nicotine into a less harmful chemical called cotinine that can then be excreted.

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Most of these deaths occur in developing countries where larger amounts of harmful chemical compounds such as toxic gases and particulate matter are released in the atmosphere.

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On the opposing side, Reid Winick, a holistic dentist who practices in New York, called it a potentially harmful chemical that can eventually cause cavities.

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Passed by voters in 1986, Prop. 65 gives any gadfly the right to sue a business with more than ten employees for exposing even one California resident to a potentially harmful chemical without proper warning.

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The machine blends iron, bleach and sodium hydroxide to form a dark purple liquid mixture of ferrate, salt and water that gets metered into the water supply. (The color disappears instantly as it reacts with the water.) Common disinfectants ozone and chlorine can turn the water cloudy or, worse, leave behind harmful chemical by-products.

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And Shuanghui's reputation was battered in 2011 when state broadcaster CCTV revealed its pork contained clenbuterol a banned chemical that makes pork leaner but can be harmful to humans.

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Between teaching classes at the University of California at Berkeley, he tends to other projects--trying to protect civilians from airborne chemical and biological threats and people in the developing world from harmful cooking smoke.

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Between teaching classes at the University of California, Berkeley he is tending to other projects--trying to protect civilians from airborne chemical and biological threats, and folks in the developing world from harmful cooking smoke.

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It was blue-sky research, but their idea was that harmful substances should be produced where they are needed, instead of being shipped in bulk from chemical factories.

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